龙芯平台下的mac地址

/本文档是个人整理,保留最终解释权,仅供参考,有jdm独家提供/
以2K1000为例，针对目前pmon版本,commit fb1e467f74bf25de83d9ddf00d043ae93ffd7ebf Date: Tue Apr 7 10:53:30 2020 +0800
内核版本,commit 103a9ad99285e010f4da02682b37b0c9b30c3608 Date: Thu Jun 11 12:59:26 2020 +0800
龙芯平台的mac地址一般有三种存储方式:
1.存放在i2c连接的eeprom中,
pmon下查看方式:

PMON> setmac

设置方式:

PMON> setmac syn0 "22 33 44 55 66 77"

代码所在位置:

Targets/LS2K/dev/eeprom.c

当然也可以通过eeprom的读写接口读写mac地址
读方式:

PMON> eepread 0 6

写方式:

PMON> eepwrite  
Please accord to correct format, for example:
        eepwrite a0 "00 11 af"
This means 0xa0 = 0x00; 0xa1 = 0x11; 0xa2 = 0xaf
PMON> eepwrite 0x00 "22 33 44 55 66 77"

2.存放在flash中的环境变量里,目前pmon存储在1M的flash中，内存存储结构为pmon+env（环境变量）+dts
pmon下查看方式:

PMON> set
        FR = 1         
        al = (usb0,0)/boot/vmlinuz
    append = "'console=ttyS0,115200 console=tty initcall_debug=1 loglevel=20'"
       al1 = (wd0,0)/boot/vmlinuz
 activecom = 0x00      
 em_enable = 0x00      
   ethaddr = 00:00:00:00:00:00   (syn0的mac地址)

设置方式:

PMON> set ethaddr 22:33:44:55:66:77
PMON> set
        FR = 1         
        al = (usb0,0)/boot/vmlinuz
    append = "'console=ttyS0,115200 console=tty initcall_debug=1 loglevel=20'"
       al1 = (wd0,0)/boot/vmlinuz
 activecom = 0x00      
 em_enable = 0x00      
   ethaddr = 22:33:44:55:66:77

目前官网代码pmon下只有一路有此环境变量
代码所在位置:
pmon/cmds/cmd_env.c
3.存放在flash中的dts中
pmon下查看方式

PMON> print_dtb ethernet0 mac-address
mac-address = [00 55 7b b5 7d f7]

设置方式:

PMON> set_dtb ethernet0 mac-address 22 33 44 55 66 77   
Programming flash 8f007b44:4000 into bfcfb000
\Verifying FLASH. No Errors found.

PMON> print_dtb ethernet0 mac-address                
mac-address = "22", "33", "44", "55", "66", "77"

代码所在位置:
Targets/LS2K/dev/load_dtb.c
如果采用此种处理方式,需要修改pmon代码如下:
Targets/LS2K/dev/load_dtb.c

 331     if(!check_prop_ok("dma-coherent", ls2k_version()) || !check_prop_ok("pci-probe-only", pci_probe_only == 1) || !check_pci_bridge_ok() \
 332     || !check_mem_args(working_fdt)) {
 333     //if(!check_mac_ok() || !check_prop_ok("dma-coherent", ls2k_version()) || !check_prop_ok("pci-probe-only", pci_probe_only == 1) || !check_pci_
 334     || !check_mem_args(working_fdt)) {
 335         u8 buff[DTB_SIZE] = {0};
 336         fdt_open_into(working_fdt, buff + 4, DTB_SIZE - 8);
 337         update_prop_flag(buff + 4, "dma-coherent", ls2k_version());
 338         update_prop_flag(buff + 4, "pci-probe-only", pci_probe_only == 1);
 339         //update_mac(buff + 4, 0);
 340         //update_mac(buff + 4, 1);

修改原因如下：
pmon的默认处理方式是,先取读取eeprom中的mac地址,然后判断是否和dts中的mac地址一样,如果不一样,就把eeprom的mac地址写入dts中,如果eeprom读写异常,就会更新默认的mac地址到dts中;

内核mac地址处理

stmmac_pltfr_probe
	ret = stmmac_probe_config_dt(pdev, plat_dat, &mac);从dts里取mac地址;
	...
	priv = stmmac_dvr_probe(&(pdev->dev), plat_dat, addr, mac);
		stmmac_check_ether_addr(priv, mac);此处设置mac地址
			1772     if (of_mac) {  //dts中的mac地址
			1773         memcpy(priv->dev->dev_addr, of_mac, ETH_ALEN);                
			1774     } else if (!is_valid_ether_addr(priv->dev->dev_addr)) {  //dev_addr为mac地址;         
			1775         priv->hw->mac->get_umac_addr((void __iomem *)   //读取控制器的40,44寄存器中的mac地址,存放在dev_addr中;              
			1776                          priv->dev->base_addr,                        
			1777                          priv->dev->dev_addr, 0);                     
			1778         if (!is_valid_ether_addr(priv->dev->dev_addr))   //判断是否无效;             
			1779             eth_hw_addr_random(priv->dev);    //如果无效,随机mac地址;                        
			1780     }                                                                 
			1781     pr_warn("%s: device MAC address %pM\n", priv->dev->name,          
			1782         priv->dev->dev_addr);

相关文件:drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
linux下设置mac地址方法:

ifconfig eth0 hw ether 22:33:44:55:55:77